A Self-assembled Organic Capsule Formed From The Union Of Six Hexagram-shaped Amphiphile Molecules

摘要

Self-assembled hollow nanostructures have a great potential for providing highly functional spaces for molecular recognition, transport, reaction, and catalysis. A number of excellent examples of discrete molecular capsules have been reported, and most are constructed by directional, noncovalent bonding such as H-bonding' and metal coordination bonding. Another key assembly strategy is to use amphiphile molecules with hydrophilic and hydrophobic parts, as seen in a variety of regular aggregates such as micelles, vesicles, and tubes triggered by the hydrophobic effect in aqueous media. In general, however, the number of components is uncertain in these aggregates. This is because each building component has no strict structural information to define a discrete structure due to the nature of less-directional interactions between the chemical components. Thus, the ensemble of hydrophobic effect and multipoint weak interactions is critical to define an entire discrete structure. Herein we present a hexagram-shaped amphiphile (1) with three hydrophilic pyridyl groups attached to a hydrophobic hexa-phenyl benzene core. This molecule aggregates in aqueous methanol to form a box-shaped structure comprised of six molecules of 1. These six components are assembled by the hydrophobic effect, van der Waals forces, and CH-π interactions. In addition, the entity can encapsulate a couple of hexa-substituted benzene molecules (3) in the hydrophobic interior space (Figure 1).